Abstract:
The present paper deals with the optimum shape design of an absolutely rigid impactor which penetrates into a semi-infinite concrete shield. The objective function to maximize is the depth of penetration (DOP for short) of the impactor; in the case of impactors with axisymmetric shapes DOP is calculated using formulas obtained by Ben-Dor et al. [1-3] with the method of local variations [4] and based on the mechanical model proposed by Forrestal and Tzou [5]. In the present paper we show that using a different class of admissible functions, more general than the axisymmetric one, better results can be obtained. To solve the formulated optimization problem we used a custom version of the particle swarm optimization method (briefly denoted by PSOA), a very recent numerical optimization algorithm of guided random global search. Numerical results show the optimal shape for various types of shields and corresponding DOP; some Ben-Dor et al. [1-3] results are compared to solutions obtained.

Abstract:
Manual construction of ontologies by domain experts and knowledge engineers is an expensive and time consuming task so, automatic and/or semiautomatic approaches are needed. Ontology learning looks for identifying ontology elements like non-taxonomic relationships from information sources. These relationships correspond to slots in a frame-based ontology. This article proposes an initial process for semiautomatic extraction of non-taxonomic relationships of ontologies from textual sources. It uses Natural Language Processing (NLP) techniques to identify good candidates of non-taxonomic relationships and a data mining technique to suggest their possible best level in the ontology hierarchy. Once the extraction of these relationships is essentially a retrieval task, the metrics of this field like recall, precision and f-measure are used to perform evaluation.

Abstract:
focusing mainly on the sophoclean tragedies oedipus rex and oedipus at colonnus, but also considering other versions of the oedipus myth and some of the iconographic documents relating to it, this article looks to show that the apotropaic element plays an important role in this mythic context. it suggests that the beliefs and practices through which the apotropaic value is expressed are rooted in the deepest grounds of the greek weltanschauung and related to conceptions of fate and the basic categories of greek religious thought. although many studies usually restrict its operation to this circle, the article argues that magic is just one of the fields in which the apotropaic code is expressed, and that the interpretation of this code requires the consideration of other discourses and the analysis of other aspects of greek culture. in theatrical presentations of the oedipus tale, the tragedy reveals the deepest meaning of the apotropaic with singular clarity.

Abstract:
following the 2006 post-electoral crisis, important changes were made to the constitution and several secondary laws in mexico. the goal of this essay is to analyze four problems derived from this new legislation: 1) a weakened autonomy of the federal electoral institute, 2) a scarcity of information in the political debate, 3) the hegemony of party elites, and 4) the uncertainty in case of contested elections. based on a detailed reading of the new norms, this essay documents such problems and discusses their potential impact in mexico's democratic process. we propose three new reforms: primary elections, runoff elections, and direct election of members of the electoral institute.

Abstract:
the development of strategy studies along the late 50 years attempted to guide the organizational search for competitive advantage. several authors defined taxonomies for strategy schools of thought after mintzberg critics to the classical use of strategic planning in the 1970？s. from their work, generally speaking, emerge the evolutionary and complementary character of the schools of thought, or the integration of their concepts. this work presents new dimensions named the four pillars of strategy: leader and executive team; strategic focus; bet (risk-taking); and resources support. these dimensions or elements were identified from classical case studies originated from literature. they were considered complementary and interdependent elements that sustain the success of an organization.

Abstract:
the objective of this article is to analyse and discuss the medical decision-making processes surrounding access by waiting-list patients to a liver transplant. on the basis of an ethnographic study that took place in a specialised hospital unit, the most significant moments in the medical decision-making are selected, showing the complex negotiation processes among the different fields of medical expertise in attendance. the most recent sociological approaches, which fall within the area of social constructivism, constitute the basis of the analytical model proposed for the study of medical decision-making in the present study.